Retractable table

ABSTRACT

The retractable table has a single, centrally disposed, vertical lift column formed of a relatively large number of relatively short sections. The relatively short sections permit the table to retract into a relatively shallow receptacle, thus obviating need for a deep well to house the column when retracted. Column actuation may be achieved by various principles of operation, including hydraulic cylinders and helically threaded sections which are rotated to extend and retract the tabletop. The table has an anti-rotation feature to prevent rotation of the tabletop relative to the underlying receptacle in which it stores. The retractable table may be provided as a “drop-in” installation, with the installer needing only to cut the required opening in the deck or floor of the vehicle in which the table is being installed, run appropriate wiring, and secure the table and its mechanism and receptacle in place.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to permanently installed,built-in furnishings having configurations convertible between adeployed and a stored condition. More particularly, the presentinvention relates to a retractable table having a telescoping centralcolumn and cantilevered table platform extending to all sides therefrom,with the column comprising a relatively large number of relatively shortsections. This enables the present table and its support column toretract into a relatively shallow depth, for compact installation andstorage.

2. Description of the Related Art

Recreational vehicles, including boats as well as road vehicles, havebecome increasingly popular as families with sufficient time anddisposable income indulge their desire to travel. In the past, most suchvehicles were relatively primitively equipped, often requiring theiroccupants to cook their meals over an outdoor campfire and to sleep insleeping bags. However, there has been a tendency to provide greaterluxury and accommodations in such boats and road vehicles, includingstandard beds, kitchenettes with complete cooking and cleaningfacilities, bathroom facilities, etc.

Such additional accommodations, of course, require additional space, andspace is already at a premium in most such vehicles, particularly thoseof smaller size. As a result, most of the components which require arelatively large area when deployed are configured to fold for storagewhen not in use. In other cases, components are engineered to providemultiple functions. An example of such is a dining table and seatingarrangement, which can be folded flat for use as a double bed. In manycases, beds and seating fold out of the way when not in use.

Even so, still greater utility and function might be provided withfurnishings which are better engineered for retraction when not in use.The present invention provides a table surface which is supported by asingle central telescoping column, with the column comprising arelatively large number of fairly short sections. This enables thepresent table to retract into a recess which requires very little depth,to avoid the need to penetrate the hull or other structure of the vesselor vehicle for installation of the present table. The presentretractable table is well suited for installation in a variety ofdifferent types of recreational vehicles, but is particularly wellsuited for installation in boats, where its supporting column fixes thetable in place and precludes movement when deployed. Different extensionand retraction mechanisms or principles may be provided for theoperation of the present retractable table.

A discussion of the related art of which the present inventors areaware, and its differences and distinctions in comparison to the presentinvention, is provided below.

U.S. Pat. No. 928,726 issued on Jul. 20, 1909 to Guy H. Witthaus, titled“Disappearing Table,” describes a table having opposed, inwardly foldingleg trusses at each end thereof. The leg trusses fold inwardly, with thetable resting level atop the folded trusses for storage. The leg trussarrangement precludes the extension of a person's legs beneath thetable, when seated at either end thereof. The extension and retractionof the Witthaus table is by manual means; no automated or poweredextension or retraction is disclosed.

U.S. Pat. No. 3,391,960 issued on Jul. 9, 1968 to Robert J. Megargle etal., titled “Motor Vehicle Interior,” describes a relatively small tablesecured to an offset, generally vertical column having limitedtelescoping capability. The Megargle et al. table can be pivoted aboutits column for positioning between the two front seats of a vehicle, orin front of or between either of the rear seats. The device cannotretract below a height somewhat above the seating surface of the frontseats, for use as an armrest between the two front seats. The entireassembly installs atop the floor of the vehicle, rather than being setinto the floor, as in the present retractable table.

U.S. Pat. No. 4,019,443 issued on Apr. 26, 1977 to Ferris E. Jones,titled “Table,” describes a non-retracting table in which the table baseextends horizontally to a swivel attachment at the base of an adjacentseat. The entire table and support may be swiveled upwardly to place thetable against the seat to which it is attached by the swivel base, forease in accessing the other seating. No retraction means is provided.

U.S. Pat. No. 4,086,859 issued on May 2, 1978 to George V. Dondero,titled “Boat Table,” describes a table having a single offset supportpost, allowing the table to be positioned asymmetrically about the baseof the support as desired. The base of the support post may be removablysecured to the underlying structure by one or more brackets. Noretraction means, either powered or manual, is provided by Dondero forhis table.

U.S. Pat. No. 4,130,070 issued on Dec. 19, 1978 to Cline E. Herrin,titled “Linearly Translatable Table Top,” describes a table which cantranslate horizontally atop a fixed base pedestal. No retraction isprovided for the pedestal or tabletop attached thereto.

U.S. Pat. No. 4,455,948 issued on Jun. 26, 1984 to Israel Torres, titled“Automotive Trunk Table,” describes a table which extends from the floorof the trunk of an automobile on a pair of parallel pantograph arms. Thedevice does not retract into or flush with the floor structure, and nosingle telescoping vertical support column is provided, as such astructure would preclude the lateral movement of the table to the rearof the vehicle, as provided by Torres.

U.S. Pat. No. 4,577,821 issued on Mar. 25, 1986 to Torbjörn Edmo et al.,titled “Lifting Table,” describes a table having a scissor-type supportstructure, rather than the single, multiple section telescoping supportpost of the present table. No retraction flush with or inset into afloor structure is disclosed by Edmo et al.

U.S. Pat. No. 4,620,741 issued on Nov. 4, 1986 to Jacobus N. Hanemaayer,titled “Combination Table Support And Trunk Access System For ARecreational Vehicle,” describes an essentially fixed table deployedover a subfloor storage area. The table includes a primary support legand a secondary brace which extends over the storage area. No retractionof the table into the storage area, or other area, is provided.

U.S. Pat. No. 5,031,563 issued on Jul. 16, 1991 to Vigbjörn Matre,titled “System For Utilizing Raisable And Lowerable Berths InCompartments Having A Limited Space,” describes a large number ofembodiments of chair, table, and berth arrangements and configurationsfor use in boats, camper vans, truck tractors, and railroad cars. Thetable configuration disclosed folds downwardly onto (but not into) thefloor on a pair of fixed length, parallel legs which pivot from thevertical to the horizontal with the table remaining secured thereto. Notelescoping support column is provided for the table.

U.S. Pat. No. 5,069,142 issued on Dec. 3, 1991 to Vigbjörn Matre, titled“Collapsible Table,” describes two different embodiments of such atable, with one of the table embodiments being essentially the same asthat described immediately above in the '563 U.S. patent to the sameinventor, but disclosed in greater detail. The other embodiment hassupport legs forming an X pattern when deployed, and which foldsimilarly to a conventional ironing board or the like. No singletelescoping support leg having a relatively large number of segments isprovided by Matre in either of his two U.S. patents.

U.S. Pat. No. 5,116,032 issued on May 26, 1992 to Julie Strachan, titled“Rollingtable With Height Adjustment And Brake Device,” describes anoperating table or the like having a hydraulic system providing limitedvertical adjustment. The table is supported on casters, rather thanbeing permanently installed, as is the present table. The hydraulicsystem forces the base downwardly against the underlying surface topreclude movement of the table when raised. The device is incapable offolding or retracting into a floor receptacle.

U.S. Pat. No. 5,220,698 issued on Jun. 22, 1993 to Keith Hannant, titled“Patient Support Tables,” describes another operating table using thesame principle and system as that of the Strachan '032 U.S. patentdiscussed immediately above. It is noted that the assignee is the samefor both the Strachan '032 and Hannant '698 U.S. patents. The samepoints of distinction noted in the discussion of the Strachan '032 U.S.patent are seen to apply here as well.

U.S. Pat. No. 5,437,236 issued on Aug. 1, 1995 to Harold R. Zeiner,titled “Multi-Functional Table With Elevational Capabilities,” describesa table having a pneumatically adjustable primary support column, with apair of opposed brace columns. Only two sections are disclosed for eachof the columns, which means that the table can only be lowered to abouthalf of its fully extended height. The table cannot be completelylowered in any event, as a foot pedal is provided at the base of theprimary column, for pumping up the column. Access to this pedal must beprovided beneath the table.

U.S. Pat. No. 5,503,086 issued on Apr. 2, 1996 to D. Stephen Hoffmann etal., titled “Table With Movable Top Surface,” describes a coffee tabletype structure in which the top surface may be extended on opposed pairsof parallel arms, somewhat like the tables disclosed in the '563 and'142 U.S. patents to Matre, discussed further above. The Hoffmantabletop can also rotate about its attachment to the underlying supportstructure. Hoffman fails to provide any means of retracting his tabletop into a recess in the underlying floor, however, and does not provideany form of substantially vertical, telescoping support column.

U.S. Pat. No. 5,947,416 issued on Sep. 7, 1999 to John R. Kraft, titled“Floor Rising Cabin Table,” describes a pair of embodiments of aretractable table configured for use in corporate aircraft, whichtypically have relatively little interior room. The primary embodimentutilizes a telescoping tube for support, but the tube has only two, orat most three, different segments. The result is a relatively deepinstallation, with the lower end of the telescoping tube extendingthrough the pressure vessel or hull of the aircraft and into the lowerwing center section, as shown in FIG. 12 and described in column 13,lines 29-57.

Such an installation would be a major effort, as penetration of thepressurized structure of an aircraft involves major engineeringconsiderations and work. The cost of the labor in such an installationwould likely be many times the cost of the table and mechanism itself.Moreover, the lower wing center sections of such aircraft generallyinclude fuel tanks or baggage storage areas, and the support column ofthe Kraft retractable table would extend into these areas.

Kraft goes on at the bottom of column 13 to the top of column 14 tostate that a mechanical screw or worm gear support structure could beconfigured to fit entirely within the pressure vessel. However, he doesnot disclose such a mechanism, and the only such mechanisms known to thepresent inventors require relatively deep receptacles, unless they use amechanism as developed by the present inventors and disclosed herein.Moreover, Kraft fails to provide any means to prevent the rotation ofthe table surface about the cylindrical telescoping column, as the tableis raised and lowered. The rectangular configuration of the folded tableof Kraft, must be aligned with its receptacle when being retracted intothe floor. Kraft would require the tabletop to be rotated by hand foralignment with the floor receptacle.

The present retractable table avoids these problems by (1) providing atelescoping column formed of a relatively large number of relativelyshort sections, thereby requiring a very shallow depth when retracted,and (2) including alignment means for all of the column segments andtheir supported table top, thereby assuring that the table top willremain aligned with its receptacle when retracted. In addition, thedrive means for extending and retracting the table support column ispreferably provided with the remainder of the mechanism for the presentinvention, as an integral package. Kraft fails to disclose any specificmeans for actuating his table, other than mere mention of a list ofknown principles.

U.S. Patent Application Publication No. 2001/13,307 published on Aug.16, 2001, titled “Safety Toe-Sensor For Lift Table,” describes a liftingdevice wherein the lift surface is raised and supported by a pair ofparallel X configuration arms, similar to the apparatus of the '821 EdmoU.S. patent discussed further above. The same points raised in thediscussion of the Edmo U.S. patent, i.e. the lack of a centraltelescoping column and lack of means for retracting so the table top isflush with the surrounding floor, are seen to apply here as well.

British Patent Publication No. 1,559,945 published on Jan. 30, 1980,titled “Operation Table,” describes a portable table for medical use,e.g. X-ray examinations or operations. The table actually comprises aseries of platform sections that may be angularly adjusted relative toone another, but their height above the base is essentially fixed atop afixed pedestal. No vertical retraction or extension mechanism isdisclosed, and the portable nature of the table does not permitretraction into a floor receptacle.

PCT Patent Publication No. WO 87/5272 published on Sep. 11, 1987, titled“Cockpit Table For Boats,” describes a table mounted on a swivel arm.The arm extends horizontally from a bracket, and rotates about itsswivel mounting. The table attaches to the distal end of the arm, by aswivel mounting. While the table and its bracket can be removed from apermanent wall mounted anchor, no retraction means is disclosed.

PCT Patent Publication No. WO 88/10,081 published on Dec. 29, 1988,titled “Table Having A Table Board The Height Of Which Is Adjustable,”describes an elevated table extending upwardly on a pedestal from alower stand. The stand includes a mechanism for raising the table asdesired, and a locking mechanism for fixing the height of the table asdesired. The table may only be lowered to the top of the stand; thestand rests atop the underlying surface. No retraction flush with theunderlying surface is possible with the table.

Japanese Patent Publication No. 64-53,999 published on Mar. 1, 1989,titled “Table Lift,” describes (according to the drawings and Englishabstract) a scissor type lifting arrangement, with one of the armscomprising a hydraulic cylinder. The mechanism can lie relatively flatbeneath the table, due to a starting linkage which initiates the tablelift when the system is actuated. This provides some initial angle forthe operation of the hydraulic lift strut to work. While the assemblycan fold to a quite thin and compact configuration, no verticaltelescoping column is provided, nor is any means of installing thedevice to lie flush with the floor of a structure, as provided by thepresent retractable table.

Japanese Patent Publication No. 2-175,595 published on Jul. 6, 1990,titled “Lifting Table,” describes (according to the drawings and Englishabstract) a table and lifting mechanism recessed into a lower surface orpit. A telescoping hydraulic cylinder is used to provide the liftingforce. However, the hydraulic mechanism comprises only two segments andcannot be collapsed to a sufficiently short height as to fit within theconfines to which the present retractable table is directed. Moreover,no means of preventing relative rotation between the upper and lowerportions of the hydraulic cylinder is apparent in the '595 JapanesePatent Publication.

Finally, British Patent Publication No. 2,242,624 published on Oct. 9,1991, titled “Operating Table,” is based upon the '032 U.S. patent tothe same inventor, discussed further above. Accordingly, the same pointsraised in the discussion of the '032 U.S. patent are seen to apply hereas well.

None of the above inventions and patents, taken either singly or incombination, is seen to describe the instant invention as claimed. Thusa retractable table solving the aforementioned problems is desired.

SUMMARY OF THE INVENTION

The present retractable table provides a compactly folding or retractingarticle for installation in boats, recreational vehicles, and cabin-sizecorporate aircraft, as desired. A key feature of the present retractabletable is its multi-segmented telescoping support strut. Rather thanbeing formed of two, or perhaps three, sections, the support strut forthe present folding table is formed of a larger number of shortersections, enabling the table to extend to full height above thesupporting surface and still retract compactly in a very shallowreceptacle.

Various means for actuating the present retractable table, includinghydraulic and helically threaded mechanical systems, are describedherein. In both systems, appropriate seals and stop means are providedin order to preclude overextension of any given pair of mating segments.Appropriate means for preventing relative rotation between extensionsegments is also provided, assuring that the table remains aligned atall times with the receptacle in which it retracts.

The present retractable table is most preferably configured as a“drop-in” assembly, including a shallow well or receptacle which may beinstalled in a cutout in the floor or deck of the vehicle, boat, oraircraft in which the device is installed. The installer need only formthe required cutout in the surface in which the present invention is tobe installed, run the appropriate electrical power and control wiring tothe installation area, secure the device within the cutout opening, andconnect the wiring. The hydraulic embodiment of the present retractabletable includes a hydraulic pump and motor power pack as an integral unittherewith, thus obviating the need for a separate hydraulic system andplumbing.

The present retractable table meets the needs of persons having cabinclass boats and aircraft, as well as those with recreational vehicles,where space is at a premium. The present table is easily extended byactuation of a switch or the like, to serve as a table for dining, chartwork, games, or other activities as desired. When the table is no longerneeded, it is easily stored by retracting into its well in the floor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic side elevation view in partial section of ahydraulically operated embodiment of the retractable table according tothe present invention in an extended state, showing its variousfeatures.

FIG. 2 is a schematic side elevation view in partial section of theretractable table of FIG. 1 in a retracted state.

FIG. 3A is a top plan view in section of an embodiment of themulti-segment hydraulic lifting column of the table of FIGS. 1 and 2,showing the means for preventing relative rotation of the columnsegments.

FIG. 3B is a top plan view of a broken away section of an alternativeembodiment lifting column, showing alternative means for preventingrotation of the segments relative to one another.

FIG. 4 is a schematic side elevation view in partial section of anembodiment incorporating a number of helically threaded column segmentsfor raising and lowering the table.

FIG. 5 is a perspective view in section of the helically threaded columnof FIG. 4, showing the mutually engaging ends of the segments forpreventing overextension of mating segments.

Similar reference characters denote corresponding features consistentlythroughout the attached drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention comprises several embodiments of a retractabletable, suited for permanent (or semi-permanent) installation in thefloor or similar structure of a cabin class boat, aircraft, orrecreational vehicle. The present retractable table generally includes abase which is installed in a cutout formed in the vehicle floor, with asingle, multiply segmented telescoping lift strut extending upwardlyfrom the base to support a table top thereon. The relatively largenumber of lift strut segments result in each segment being relativelyshort, allowing the lift strut and table to retract flush with the floorwithout requiring any substantial depth below the floor for theretracted lift strut.

FIG. 1 of the drawings provides a schematic side view in partial sectionof a first embodiment of the present retractable table apparatus in itsextended configuration, designated by the reference numeral 10. Thepresent retractable table assembly 10 is configured for permanent, or atleast semi-permanent, installation in the deck D or floor of a cabinclass boat or yacht, a cabin class aircraft, or recreational vehicle. Afloor installation base 12 includes a peripheral floor attachment flange14, which secures atop the deck D or floor using conventional fastenersor other suitable attachment means. The flange 14 preferably tapersoutwardly to a thin edge, in order to avoid forming a tripping hazard.The installation base 12 has a shallow tabletop recess 16 located justbelow the upper surface 18 of the flange 14, for receiving the table 20of the present invention when it is retracted. The tabletop recess 16 isdimensioned to closely fit the table 20, with the cutout formed in thedeck D preferably dimensioned to fit closely about the exterior of thetabletop recess 16 in the installation base 12.

The installation base 12 further includes a lift strut receptacle 22 inthe tabletop recess portion 16 thereof, and depending below the tabletoprecess 16. The lower end of the lift strut for the tabletop 20 isaffixed within this lift strut receptacle 22. The lift strut 24 isformed of a relatively large number of relatively short, concentric,telescoping sections or segments, e.g. a lower or base segment 24 aaffixed within the lift strut receptacle 22, a series of fiveintermediate strut segments 24 b through 24 f which are extendable fromthe base segment 24 a, and an uppermost segment 24 g to which the tabletop 20 is affixed. More or fewer lift strut segments may be provided asdesired, depending upon the height requirement for the extended tabletop20 and the depth limitation for the lift strut receptacle 22. However, aseries of seven such lift strut segments 24 a through 24 g has beenfound to provide a suitable compromise in lift height and depth of theretracted mechanism, without requiring undue complexity.

Preferably, the lift strut assembly 24 comprises a series of concentrichydraulic cylinders, with conventional seals disposed between eachsegment. A power package comprising a hydraulic pump 26 and fluidreservoir 28 is situated beneath the floor installation base 12, e.g.secured to the lift strut receptacle 22, and provides hydraulic fluidunder pressure by means of inlet and outlet lines 30 and 32 between thepump 26 and the base cylinder or segment 24 a. A conventional electricmotor and remote switch (not shown) may be used to actuate the pump 26as desired to extend or retract the column 24 and table 20.

FIG. 2 of the drawings provides an elevation view in partial section ofthe retractable table mechanism 10 in its retracted state. In FIG. 2,the central lift strut 24 has been collapsed or retracted, with thesmaller diameter segments nesting within the larger diameter segments.The segments forming the outer sleeve assembly 34 are nested in the samemanner. The large number of relatively short segments forming the liftstrut 24 and outer sleeve assembly 34, allow the table top 20 to beretracted so that its upper surface 36 is flush or essentially coplanarwith the upper surface 18 of the peripheral mounting flange 14 of thefloor installation base 12, while still providing a relatively shallowdepth for the lift strut receptacle 22 and its removable access cover38.

As the hydraulic cylinder segments 24 a through 24 g are circular incross section, there is nothing per se to preclude relative rotation ofany of the cylinder segments relative to one another. This may not becritical in the case of a round table 20 and correspondingly shapedcircular table receptacle 16 in the installation base 12, but it isimportant where a non-circular tabletop 20 and correspondingly shapedrecess 16 are provided. Accordingly, the present retractable tablemechanism 10 includes an outer sleeve assembly 34, as noted above, whichserves to maintain the alignment of the tabletop 20 with its underlyingrecess 16. The outer sleeve assembly 34 comprises a base sleeve 34 a(which may be the same as the lift strut receptacle 22), a series ofconcentric, telescoping intermediate sleeves, e.g. sleeve segments 34 bthrough 34 f, and an uppermost sleeve segment 34 g. Preferably, thenumber of outer sleeve segments 34 a through 34 g is the same as thenumber of hydraulic cylinder segments 24 a through 24 g, although thelimiting factor for the extension and retraction height of the assembly10 is the length of the longest cylinder or sleeve segment, if they arenot of equal length.

The series of outer sleeve segments 34 a through 34 g each include someform of cooperating linear engagement means to preclude relativerotation between each of the immediately adjacent segments, and thusbetween the lift strut receptacle 22 comprising the lowermost outersleeve segment 34 a and the uppermost outer sleeve segment 34 g with itsattached table top 20. FIGS. 3A and 3B illustrate examples of suchanti-rotation means. In FIG. 3A, a series of outer sleeve segments 34 athrough 34 g concentrically surround the inner lift strut segments 24 athrough 24 g. The outer sleeve segments 34 b through 34 g all include atleast one (and preferably two or three) linear channel(s) 40 formed intheir outer walls, with the segments 34 a through 34 f all havingcorresponding linear ribs 42 formed along their inner walls and engagingthe corresponding channels 40 of the inwardly adjacent segments. Theengagement of the channels 40 and ribs 42 prevent relative rotationbetween adjacent segments, thus preventing rotation of the innermostsegment 34 g, and its attached table top 20 (shown in FIGS. 1 and 2)relative to the outermost base segment 34 a. It will be seen that theorientation of the channels and ribs may be reversed if so desired, withthe ribs extending outwardly and channels extending inwardly, or otherengagement means may be used as desired.

FIG. 3B provides a broken away plan view in section of an alternativeouter sleeve assembly of non-circular cross section, designated assleeve assembly 35. The inner hydraulic cylinder assembly 24, comprisingsegments 24 a through 24 g, is essentially identical to the assembly 24shown in FIGS. 1 and 2. However, the outer sleeve assembly 35 is formedof a series of non-circular segments 35 a through 35 g, with each of thesegments having the same non-circular shape and being progressivelysmaller to fit closely within one another. (It should be noted thatclearances between segments 24 a through 24 g and 35 a through 35 g inFIG. 3B, and clearances between segments 24 a through 24 g and 34 athrough 34 g in FIG. 3A, are exaggerated for clarity in the drawingFigs.) The non-circular configuration of the outer sleeve segments maybe square, as shown, or may alternatively be of any regular or irregularshape as desired, so long as they share the same shape but varyprogressively in size from the largest to the smallest segment, in orderto fit closely with one another and preclude relative rotation of any ofthe segments.

To this point, a hydraulic operating system has been described forextending and retracting the table top of the present invention.However, it will be seen that other actuating mechanisms may beprovided, as desired. One such mechanism may comprise a series ofconcentric, helically threaded segments 124 a through 124 g forming athreaded lift strut 124, as illustrated in FIG. 4 of the drawings. Anouter sleeve assembly, e.g. sleeve assembly 34 comprising segments 34 athrough 34 g, is provided to prevent rotation of the table top 20relative to the base 12 and its table top recess 16. The helicallythreaded lift strut assembly 124 operates by means of an electric (oralternatively, hydraulic) motor 44, which communicates with a drivewheel 46 extending from the lower end of the first helical segment 124a. Conventional belt or chain drive, gearing, etc. (not shown) may beused to connect the rotation of the motor 44 to the lift strut drivewheel 46. (Such an electric motor 44 may also be used to drive thehydraulic pump 26 of the hydraulically actuated embodiment of FIGS. 1and 2.)

The helically threaded lift strut embodiment of the present retractabletable is illustrated in its extended or deployed position in FIG. 4.From an initial stored or retracted configuration, rotation of the drivewheel 46 also rotates the first helically threaded segment 124 a, whichcauses the second segment 124 b to unthread from its stored positionwithin the first segment 124 a. When the second segment 124 b hasreached the end of its threaded extension from the base segment 124 a,it will also be forced to rotate, thereby causing the third segment 124c to unthread from the second segment 124 b. This sequential unthreadingoperation will continue until all of the lift strut segments 124 athrough 124 g have unthreaded themselves from one another to theirlimits, thus causing the table top 20 to rise to its fully deployedposition as shown in FIG. 4. While the unthreading of the segments 124 athrough 124 g has been described as a sequential operation, it should benoted that the order of relative rotation may vary depending uponfriction between segments, and is not critical.

It will be understood that some means is required for preventing theoverextension of the various segments, in order to prevent segments fromdisassembling from one another as they extend. FIG. 5 provides adetailed perspective view in section of the outer sleeve assembly 34 andits segments 34 a through 34 g, as well as the helically threaded liftstrut 124 and its segments 124 a through 124 g, showing theoverextension stop means provided. Each of the outer sleeve segments 34a through 34 f includes an upper, inwardly extending flange 48, witheach of the segments 34 b through 34 g having a lower, outwardlyextending flange 50 of smaller inner diameter than the outer diameter ofthe corresponding opposite flange 48. Thus, when the outer sleeve 34extends to its maximum height, each of the outer flanges 48 is preventedfrom overextension by its contact with the overlying inner flange of thenext sleeve unit or segment. This same principle may be used to limitthe extension of the hydraulic strut assembly 24 shown in FIGS. 1 and 2,as well, or other overextension stop means (e.g., conventional grooveswith internal and/or external snap rings, etc.) may be used.

Overextension of the helically threaded lift strut segments 124 athrough 124 g is prevented in much the same manner, with each of thesegments 124 a through 124 f having an upper, inwardly extending flange52 and each of the segments 124 b through 124 g having a lower,outwardly extending flange 54. Alternative overextension preventionmeans may be used, as noted above in the description of such means forthe lift strut 124. However, each of the inwardly extending flanges 52of the helically threaded lift strut segments 124 a through 124 fincludes internal threads 56, which engage the external threads of theadjacent inner lift strut segment. In this manner, rotation of any liftstrut segment relative to its immediately adjacent lift strut segmentresults in the extension or retraction of the two segments relative toone another, depending upon the relative direction of rotation.

As noted further above, the rotational extension or retraction of thehelically threaded segments 124 a through 124 g may be sequential, or insome other order, depending upon relative friction between adjacentsegments. However, the order of extension or retraction is not critical,as when any two segments have reached their fully extended state, theabutting outward and inward flanges 52 and 54 of any two mating segmentsprevent further extension and cause the two segments to rotate togetheras one unit, thereby transferring relative rotation to other segments ofthe assembly until extension is complete.

While not shown in the drawings, additional lower, inwardly extendingflanges or upper, outwardly extending flanges may be provided oppositetheir counterparts 48, 52 and 50, 54 on the outer sleeve segments 34 athrough 34 g and the lift strut segments 124 a through 124 g (or thehydraulic lift strut segments 24 a through 24 g of FIGS. 1 and 2). Thisserves to prevent the higher segments from dropping through the lowerand larger diameter segments, when the assemblies are retracted. Again,other means may be used, e.g. circumferential grooves and snap rings,etc.

In conclusion, the present retractable table in its various embodimentsprovides a much needed means of creating a table for dining, chart work,games, or any other suitable purpose, which may be retracted into thefloor for unobtrusive storage when not needed. A simple throw rug or thelike may be spread over the retracted table surface when floor space isneeded, in order to protect the table surface when retracted.Alternatively, folding extension leaves may be provided from the edgesof the table to expand the surface area of the table when in use, withthe leaves folding over the top of the table to protect the tablesurface when retracted into the floor. The present retractable tableassembly is easily installed, as it is provided in an installation basewhich is easily secured within the floor, once the appropriate cutouthas been formed in the floor. Accordingly, the present retractable tablewill be favorably received by owners of cabin class boats and aircraft,recreational vehicles, and others who have need for a retractable tablesurface within a confined area.

It is to be understood that the present invention is not limited to theembodiments described above, but encompasses any and all embodimentswithin the scope of the following claims.

1. A retractable table, comprising: a floor installation base having: aperipheral floor attachment flange having at least an upper surface; ashallow tabletop recess defined within said floor installation base, anddepending below said floor attachment flange; a lift strut receptacledisposed within said floor installation base, and depending below thetabletop recess; a single lift strut having a plurality of concentric,telescoping lift strut segments retractably extending from said liftstrut receptacle; a power package affixed beneath said floorinstallation base, and communicating with said lift strut; and a tabletop having at least an upper surface, the table top being disposed atopsaid lift strut, the upper surface of the table top being disposedsubstantially flush with the upper surface of said floor attachmentflange when said table top is completely retracted.
 2. The retractabletable according to claim 1, further including: an outer sleeveconcentrically disposed about said lift strut, the outer sleeve having:a plurality of concentric, telescoping outer sleeve segments; and meansfor precluding relative rotation between each of said outer sleevesegments.
 3. The retractable table according to claim 2, wherein saidlift strut and said outer sleeve each comprise: a base segment extendingfrom said lift strut receptacle; a top segment affixed to said tabletop; and a plurality of intermediate segments between the base and topsegments.
 4. The retractable table according to claim 2, furtherincluding overextension stop means disposed upon each of the segments ofsaid lift strut and the segments of said outer sleeve, for precludingseparation of adjacent and mating said segments from one another.
 5. Theretractable table according to claim 1, wherein said power packagecomprises a hydraulic pump and reservoir driven by an electric motor. 6.The retractable table according to claim 1, wherein said lift strutcomprises a plurality of concentric, helically threaded, rotationallyextendable and retractable lift strut segments.
 7. The retractable tableaccording to claim 6, wherein said power package comprises an electricmotor rotationally driving said lift strut for the selective extensionand retraction thereof.
 8. A retractable table, comprising: a floorinstallation base; a tabletop; a single lift strut disposed between saidfloor installation base and said table top, the lift strut having aplurality of concentric, telescoping lift strut segments; an outersleeve concentrically disposed about said lift strut, the outer sleevehaving: a plurality of concentric, telescoping outer sleeve segments;and means for precluding relative rotation between each of said outersleeve segments.
 9. The retractable table according to claim 8, whereinsaid for means precluding relative rotation between each of said outersleeve segments is selected from the group consisting of mating keys andchannels on adjacent segments and closely fitting, non-circularsegments.
 10. The retractable table according to claim 8, furtherincluding overextension stop means disposed upon each of the segments ofsaid lift strut and the segments of said outer sleeve, for precludingseparation of adjacent and mating said segments from one another. 11.The retractable table according to claim 8, wherein said floorinstallation base further includes: a peripheral floor attachment flangehaving at least an upper surface; a shallow tabletop recess definedwithin said floor installation base, and depending below said floorattachment flange; a lift strut receptacle disposed within said floorinstallation base, and depending below said table top recess, said liftstrut retractably extending from said lift strut receptacle of saidfloor installation base; and a power package affixed beneath said floorinstallation base, and communicating with said lift strut; wherein thetable top has at least an upper surface, the table top being disposedatop said lift strut, the upper surface of the table top being disposedsubstantially flush with the upper surface of said floor attachmentflange when the table top is completely retracted.
 12. The retractabletable according to claim 11, wherein said lift strut and said outersleeve each comprise: a base segment extending from said lift strutreceptacle; a top segment affixed to said table top; and a plurality ofintermediate segments disposed between the base segment and the topsegment.
 13. The retractable table according to claim 11, wherein saidpower package comprises a hydraulic pump and reservoir driven by anelectric motor.
 14. The retractable table according to claim 8, whereinsaid lift strut comprises a plurality of concentric, helically threaded,rotationally extendable and retractable lift strut segments.
 15. Theretractable table according to claim 14, further including an electricmotor rotationally driving said lift strut for the selective extensionand retraction thereof.
 16. A retractable table, comprising: a floorinstallation base; a tabletop; a single lift strut disposed between saidfloor installation base and said tabletop, the lift strut having: aplurality of concentric, helically threaded, rotationally extendable andretractable lift strut segments; a base segment extending from saidfloor installation base; a top segment affixed to said table top; and aplurality of intermediate segments disposed between the base segment andthe top segment.
 17. The retractable table according to claim 16,further including an outer sleeve concentrically disposed about saidlift strut, the outer sleeve having: a plurality of concentric,telescoping outer sleeve segments; and means for precluding relativerotation between each of said outer sleeve segments.
 18. The retractabletable according to claim 17, wherein said means for precluding relativerotation between each of said outer sleeve segments is selected from thegroup consisting of mating keys and channels on adjacent segments andclosely fitting, non-circular segments.
 19. The retractable tableaccording to claim 17, further including overextension stop meansdisposed upon each of said segments of said lift strut and of said outersleeve, for precluding separation of adjacent and mating said segmentsfrom one another.
 20. The retractable table according to claim 16,wherein said floor installation base further includes: a peripheralfloor attachment flange having at least an upper surface; a shallowtabletop recess disposed within said floor installation base, anddepending below said floor attachment flange; a lift strut receptacledisposed within said floor installation base, and depending below saidtable top recess, said lift strut retractably extending from said liftstrut receptacle of said floor installation base; an electric motorrotationally driving said lift strut for the selective extension andretraction thereof; said table top having at least an upper surface,said table top being disposed atop said lift strut, the upper surface ofsaid table top being disposed substantially flush with the upper surfaceof said floor attachment flange when said table top is completelyretracted.